1. Field of the Invention
The present invention relates to a portable communication terminal using a digital communication system which includes a cellular phone, a Personal Digital Assistant (PDA), a Personal Communication System (PCS), a camera phone, a game phone, an internet phone and the like, and more particularly to a portable communication terminal having a housing which can perform both a sliding movement and folding movement.
2. Description of the Related Art
In general, “portable communication terminal” means an electronic device which a user can carry with him/her while communicating with another user by wireless. In consideration of portability, design of such a portable communication terminal has tended not only toward compactness, slimness and lightness, but also toward providing multimedia capabilities to allow the user to pursue a wider variety of functions. In particular, future portable communication terminals will be not only used for many functions while still being compact and light, but also be modified to be suitable for functioning in a multimedia environment and for providing internet access and functions.
Conventional portable communication terminals may be classified into various types according to their appearance, such as bar-type portable communication terminals, flip-type portable communication terminals, and folder-type portable communication terminals. The bar-type portable communication terminal has a single housing shaped like a bar. The flip-type portable communication terminal has a flip panel which is pivotably mounted to a bar-shaped housing by a hinge unit. The folder-type portable communication terminal has a folder coupled to a single bar-shaped housing by a hinge unit in such a manner that the folder can be rotated in order to be folded or unfolded from the housing.
Further, portable communication terminals may be classified as neck wearable type terminals and wrist wearable type terminals, according to the position or the way in which a user wears the terminal. The neck wearable type terminal is one which a user wears around the neck using a lanyard or necklace, while the wrist wearable type terminal is one which a user wears around the wrist.
Additionally, portable communication terminals may be classified as rotation-type terminals and sliding-type terminals according to the methods of opening and closing the terminals. In the rotation-type portable communication terminal, two housings are coupled to each other in a manner that one housing rotates to be opened or closed relative to the other while facing each other. In the sliding-type portable communication terminal, two housings are coupled to each other in a manner that one housing slides to be opened or closed relative to the other. The various classifications of portable communication terminals are easily understood by those skilled in the art.
Further, conventional portable communication terminals are now capable of allowing a voice communication as well as a high-speed data communication. That is, as consumer demands have increased, various services have been provided using wireless communication technology for transmitting and receiving data at a high speed.
It is a present tendency that a camera lens is mounted to the portable communication terminal, and that it is possible to transmit image signals and the like. As such, present portable communication terminals are provided with an embedded or external camera lens module. Therefore, it is possible to perform image communication with a desired partner or to photograph a desired subject.
However, the conventional sliding type portable communication terminal includes two housings, one of which can slide in only one direction with respect to the other housing. Also, the conventional sliding type portable communication terminal usually has only one display unit. Therefore, the conventional sliding type portable communication terminal cannot display a landscape mode screen. Likewise, the conventional swing type portable communication terminal also has only one display unit. Therefore, it is inconvenient for a user to view a landscape mode screen by using the conventional swing type portable communication terminal. Furthermore, the conventional sliding type or conventional swing type portable communication terminal has a small number of keys, so that it is inconvenient for the user to operate the keys with both hands.